As the demand for wireless communication systems increase, there is a need for communications systems and methods that provide networks with higher capacity and reliability. Multiple-input multiple-output (MIMO) techniques, based on multiantenna multiplexing and diversity, can be used to provide high data rates and better reliability. Space-time codes and subsequently space-time block codes (STBC) have been introduced as methods which efficiently use the available space-time resources in multiantenna communication systems. Orthogonal space-time block codes (OSTBCs), as one type of space-time code, can be used to improve diversity while only requiring a linear complexity decoder. Because of their low complexity in encoding and decoding, OSTBCs have been used widely.
However, there is a need for improved systems which can improve performance without adding undue complexity.